Internal combustion engine control



June 22, 1943. R. M. NARDONE 2,322,584

INTERNAL COMBUSTION ENGINE CONTROL Filed Oct. 51, 1940 28 lNSl/LA T/ON4/ ,/2

INVENTOR. Ro/rreo M. Nara/one zmfi 42 4.

Mam 4 Patented June 22, 1943.

INTERNAL COMBUSTION ENGINE CONTROL Romeo M. Nardone, Westwood, N. 1.,assignor to Bendix Aviation Corporation, South Bend, Ind, a cofporationof Delaware Application October 31, 1940, Serial ship. 363,781 6 Claims.(Cl. 123186)f w This invention relates to internal combustion engines,and particularly to the control of the ignition of fuel in thecombustion chambers of such engines.

An object of the invention is to provide means for preventing prematureignition of fuel in any engine cylinder during the starting period, thatis, the periodin which the engine is being rotated (cranked) byexternally energized starting mechanism.

' With the commonly used low speed starting mechanism, the crankingspeed oi tin-aircraft engine is too low to permit of sufiicient ignitioncurrent generation by engine-driven means; and as the main magneto, ormagnetos, of the engine are engine-driven, it follows that they are noteffective at these low cranking speeds. This deficiency is ordinarilycompensated for by providing auxiliary ignition current producing means,operable during the startlngperiod, and not dependent upon rotationalspeeds for its effectiveness--an induction coil, for example. whoseprimary winding is fed by current from a storage battery,'and whosesecondary winding connects with the main distributor, through which itdelivers a shower of high tension sparks vat the several cylinderspark-plug gaps; but in order to guard against premature ignition theconnection to the distributor is spaced from the main magneto connectionby an amount that is suidcient to delay the spark until the piston haspassed top dead center. whereas the main magneto connection results-whenthe speed becomes suiilcient to develop any spark at allin a sparkoccurrence slightly in advan e of arrival of the piston at top deadcenter.- While such advance firing of the fuel is desirable at normalrunning speeds, it is quite undesirable during the starting period, forat that period there is not sufllcient momentum to continue the pistonon is upward course, and there will result a reverse rotation, or"back-fire of the engine.

.Such reverse rotation-may seriously damage the starting mechanism; andthe present invention has for an object the elimination of thepossibility of such an advance spark during the starting process.

A further object is to provide means for rendering an advance sparkimpossible during starting, said means being so constructed as to assureproduction, of such advance sparks as soon as the starting process iscompleted A further object is to provide means for inter locking theignition circuitswith a. circuit leading the starting (cranking)mechanism,- whereby the timing of the ignition sparks is made to dependupon whether or not the starting mechanism is operating; the timingbeing shifted automatically when the starting mechanism operation isdiscontinued.

These and other objects of the "invention will become apparent frominspection of the following specification when read with reference tothe accompanying drawing wherein is illustrated the preferred embodimentof the invention. It is to be expressly understood, however, that thedrawing is for the purpose of illustration only. and is not designed asa definition of the limits of the invention, reference being had to theap pended claims for this purpose.

In the drawing reference character 5 designates a switch housing ofinsulating material within which is an arm 8 rotatable on a spindle I atthe center of the housing; the arm 6 being These contact elements areadapted to receive conducting wires connected as follows: contact i, awire it, to the induction coil "-41, feeding the auxiliary rotatingcontacts i6 and i1 oi-the ignition current distributors It and 19,respectively; the latter being rotatable by gears or other parts drivenfrom the engine crankshaft, as are also the main magnetos 2| and 22; thesaid wire 4| also leading to the terminal post 23 of the starter 24,whose associated terminal post 26 is the terminus of the return feed 21leading back to the negative side of the battery 28; contact II, to theprimary winding of main magneto 2|; and contact ID, to the primarywinding of main magneto 22; the use of dual ignition" (two spark-plugsper cylinder) being assumed for the illustrated system, a1 though ofcourse the invention is applicable to single or triple ignition as well.

As above indicated the contact arm 6 is insulated from the spindle 1,and such insulation is indicated at 3| in the drawing. This insulation3| permits the segment I to complete circuits, by way of battery 28 andcontact strip I, to the coil and starter 24.

The extension l2 of arm 6 likewise is provided with two electricallydistinct conducting segments 4!) and 4| mounted on the extension l2, thelatter being of insulating material. The spacing of the contact strips40 and 4| is such as to cause them to have engagement at all times withthe contacts H and I0, respectively, although in certain positions theengagement will involve the non-conducting ports 43, 44 and 45, theportion 43 being on the strip 40, and the portions 44 and 45 on thestrip 4|. All conducting portions of the strips 40 and 4| are groundedas indicated and therefore the associated magneto primary windings aregrounded whenever the contacts l and ||,o'r either of them, areregistering with a conducting portion of the strips, 4|) and 4|; thegrounded condition of the circuit being broken whenever from aconducting portion to a non-conducting portion.

In operation, the arm 6 is first rotated from the at rest" or deadposition,,in which it is shown, and is caused to come to rest in theposition designated position A on the drawing. In this position both thestarter 24 and the auxiliary ignition circuit are energized, whereforecrankshaft rotation begins and igniting sparks occur in the severalcylinders as the pistons therein passslightly beyond top dead center, ontheir successive power strokes-this delayed firing being due to thetrailing position of contacts l6 and H, in relation to main magnetocontacts 5| and 52, respectively, ofthe distributors. During thisstarting period the said contacts 5| and 52 are dead, due to the.grounded condition of the contact strips 40 and 4| on sector l2, saidstrips being then .in circuit with the main magneto primary windings.

When the engine fires and starts to run under its 'own power, theoperator will move arm. 6 to position B, in which position both magnetos2| and 22 will become operative simultaneously, due to the establishmentof registry between the non-conducting portions 43 and 444 on theone-hand, and the contacts II and" I0, respectively, on .the other,therebyvinterrupting the grounded connections of the primary windings ofthe magnetos, and thereby enabling their conventional circuit breakers(shown at 49 and 50, respectively) to function and cause current to beperiodically induced in the secondary windings which feed thedistributor contact arms 5| and 52, respectively. If it is desired thatthis shift from the auxiliary ignition circuits to the main magnetocircuits be of an over-lapping nature as a safety precaution against atemporary hiatus in ignition current supply, the spacing of thenon-conducting portions 43 and as may be made to have such arelationship to the spacing of the auxiliary ignition segment 9 thatregistry will be effected between said portions it and 45 and thecontact pins H and I0, respectively, just prior to the breaking off ofregistry between segment 8 of arm 6 and the terminal edge of the strip9; but of course, it will be understood that when the angular swing ofthe arm definitely reaches position B there will, of course, be acomplete interruption of current flow to the strips so that during thenormal running of the engine, the ignition will be derived solely fromthe main magneto circuits, the distributor arms 5| and 52 of which willfunction to produce ignition in the several cylinders as the pistonstherein successively approach top dead center on their respective comtheregistry shifts pression strokes. Thus there will be effected anautomatic advance of the ignition point as compared with that whichprevails during the starting period when the auxiliary ignition circuitsrather than the main magneto circuits were functioning.

When the engine is to be cut out, the arm 6 will be returned of course.to the dead position shown. Should it be desired to cut out onemagneto, but not the other,'arrn 6 may be moved to position C orposition D depending upon which magneto it is desired to cut out; suchindividual cutting out of magnetos being desirable on differentoccasions as, for example, to test the performanceof one as against theother. When the arm is moved to position C, the sparkplugs associatedwith magneto 22 will be cut out, for in this position contact pin IDwill register with the grounded conducting portion 41 of the strip 4|,while the contact pin M will register with the non-conducting portion ofthe strip 40 and therefore the magneto 2| will continue to function.Conversely, in position D magneto 2| will cease to function due to theregistry of pin H with grounded conducting portion 48 of strip 40;magneto 22, however,-now being effective by reason of the registry ofpin II] with the nonconducting portion 45 of strip 4|. The terminal 23,26 of the starting unit may be the terminals of an electric motorconstituting the prime mover of such a unit, or they may be theterminals of any other electrical starter control, such as the firingelectrodes of a powder igniting device, where combustible powder is thesource of starting energy (as in my Patent No. 2,207,936, granted July16, 1940).

The induction coil assembly BI is, of course, of conventional design andincludes, in addition to the windings 46 and 41, the usual contacts 62and condenser 63, all of which function in the usual manner (see PatentNo. 1,214,555 to B. M. Leece).

What is claimed is:

The combination, with an internal combustion engine magneto, of enginestarting means comprising a member for imparting initial rotary movementto the engine and an induction coil for facilitating ignition of fuelduring operation of said member, and common means for controllingenergization of both said starting means and said induction coil, saidcommon means also acting to render said magneto ineffective so long assaidmember and induction coil remain energized.

2. The combination, with an internal combustion engine magneto and anadvance-spark mechanism in circuit therewith, of engine starting meanscomprising a member for imparting initial rotary movement to the engineand an induction coil for facilitating ignition of fuel during operationof said member, and common means for controlling energization of bothsaid starting means and said induction coil, said common meanscomprising a switch mechanism which also prevents energization of saidmagneto during the starting period, thus preventing premature passage ofcurrent to said advancespark mechanism, and consequent reverse rotationof the engine.

3. The combination, with an internal combustion engine, of separatestarting and running ignition circuits therefor, a starting motor forfacilitating starting of the engine, an energization circuit for saidstarting motor, and common means for preventing simultaneousenergization of all said circuits.

4. The combination, with engine starting mechanism. of ignition circuitsfor said engine,

said circuits including a pair-of engine-driven current distributorelements and stationary con tact elements successively engaged thereby,but at different times corresponding to diiIerent points in the enginespower cycle, and means for controlling said starting mechanism andignition circuitsin such manner as'to prevent flow of ignition currentto both said distributor elements simultaneously. I Y

5. The combination with engine starting mechanism, of ignitioncircuitsfor said engine, said circuits including a. pair of engine drivencurrent distributor elements and stationary contact elementssuccessively engaged thereby, but

at different times corresponding to different points in the engine'spower cycle, and means for controlling said starting mechanism andignition circuits in such manner as to cause the ignition current toflow, first, through one of said distributor elements and then throughthe other,

to vary the ignition timing in accordance with the setting of saidcontrolling means, said lastnamed means including a switch mechanismwhich, in one position, causes energization of said starting mechanismand one ignition circuit, and in another position causes deenergizationof said starting mechanism and said one ignition circuit, whilesimultaneously causing energization of another of said ignitioncircuits, wherein the timing differs from that of said first-namedcircuit.

6. The combination, with an internal combusa tion engine magneto, ofenginestarting means comprising a member for imparting initial rotarymovement to the engine and an induction coil for facilitating ignitionof fuel during operation of said member, and common means forcontrolling energlzation of both said starting means and said inductioncoil, said common means comprising. a switch mechanism which alsocontrols energization of said magneto, and said switch mechanismincluding a plurality of stationary contact segments and a singlerotatable contact member 'e'ngageable selectively therewith, andmeans.for supporting said segments in such spaced relationship as to preventsimuitaneous energization of both said magneto and said induction coil.

ROMEO M. NARDONE.

